CN116224443A - Electrode station network system for goaf fire source detection, layout method and test method thereof - Google Patents
Electrode station network system for goaf fire source detection, layout method and test method thereof Download PDFInfo
- Publication number
- CN116224443A CN116224443A CN202310049327.7A CN202310049327A CN116224443A CN 116224443 A CN116224443 A CN 116224443A CN 202310049327 A CN202310049327 A CN 202310049327A CN 116224443 A CN116224443 A CN 116224443A
- Authority
- CN
- China
- Prior art keywords
- electrode
- goaf
- station
- electrode station
- ground
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
- G01V3/00—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A90/00—Technologies having an indirect contribution to adaptation to climate change
- Y02A90/30—Assessment of water resources
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Environmental & Geological Engineering (AREA)
- Geology (AREA)
- Remote Sensing (AREA)
- Physics & Mathematics (AREA)
- General Life Sciences & Earth Sciences (AREA)
- General Physics & Mathematics (AREA)
- Geophysics (AREA)
- Measurement Of Resistance Or Impedance (AREA)
Abstract
The invention discloses an electrode station network system for goaf fire source detection, and a layout method and a test method thereof, wherein the electrode station network system comprises a roadway electrode station, a goaf electrode station and a main roadway reference electrode station, wherein the roadway electrode station, the goaf electrode station and the main roadway reference electrode station are respectively and sequentially arranged below the ground of coal rocks in a goaf under a coal mine at intervals; each electrode station comprises a detection wire, flexible graphite cloth, a wire mesh, a graphite cement base and a grounded metal electrode; measuring the coal rock resistivity rho of the ground in the goaf through a rock resistivity measuring instrument, and calculating the theoretical grounding resistance R of a single electrode station g And thus the theoretical ground resistance R of the electrode station g And respectively determining the arrangement space of the roadway electrode stations, the arrangement space of the goaf electrode stations and the arrangement space of the main roadway reference electrode stations according to the determined size of the pre-arranged electrode stations. The invention has the effects of high temperature resistance, corrosion resistance, good stability and high detection precision, and is extremely suitable for detecting hidden fire sources in a coal mine goaf in an extreme environment of a coal mine.
Description
Technical Field
The invention belongs to the technical field of coal mine fire source detection electrodes, and particularly relates to an electrode station network system for goaf fire source detection, a layout method and a test method thereof.
Background
The conductive type electrical method is a mature geophysical prospecting method for observing the current field of the earth medium through the grounding electrode, and common means comprise a resistivity method, a natural electric field method, a charging method, an induced polarization method and the like, and is widely applied to exploration work in the fields of regional geology, hydrogeology, engineering geology, environmental geology, coal field geology and the like.
The grounding electrode is used as a sensor probe for conducting an electric method and can be used as a sensor for detecting regional fire sources, and the grounding electrode mainly comprises three types of metal electrodes, liquid non-polarized electrodes and solid non-polarized electrodes. The metal electrode is mainly made of copper and iron materials, the appearance of the metal electrode is in a drill rod shape, and the conductive mode is electronic conduction; the liquid non-polarized electrode is CuSO 4 Electrolyte solutions such as NaCl and the like are filled in the insulated electrode tank, the bottom is close to the object to be measured by adopting a cork or a ceramic diaphragm, and the conductive mode is ion conduction; the solid unpolarized electrode is mainly composed of PbCl 2 The metal salt such as AgCl is mixed with kaolin, gypsum and the like and cured, and the conductive mode is ion conduction. The above electrodes cannot be practically applied to coal field fire source detection, in particular, the metal electrode has poor corrosion resistance in extreme environments of underground coal mine, the liquid unpolarized electrode and the solid unpolarized electrode are difficult to bear the impact caused by falling rocks of underground coal mine, cannot bear the high temperature of more than 200 ℃ and needs daily maintenance, so that the severe environmental requirements of goafs of underground coal mine cannot be met.
In addition, in the prior art, the conventional detection mesh cloth is arranged on the ground surface, and the arrangement method comprises the following steps: the distribution points are not in direct contact with the goaf under the coal mine, and are generally distributed according to the profile arrangement and the regular network measurement arrangement, and the point distance and the line distance are set according to the requirement of exploration precision. Because the earth surface distribution pole is a certain distance from the underground goaf fire source, the detection accuracy is not high.
Disclosure of Invention
Aiming at the problems, the invention overcomes the defects of the prior art, and provides an electrode station network system with high temperature resistance, corrosion resistance, good stability and high detection precision for detecting the fire source in the goaf of the coal mine, and a layout method and a test method thereof.
In order to achieve the above purpose, the present invention adopts the following technical scheme.
In one aspect, the invention provides an electrode station network system for goaf fire source detection, which comprises a roadway electrode station, a goaf electrode station and a main roadway reference electrode station, wherein the roadway electrode station, the goaf electrode station and the main roadway reference electrode station are respectively arranged below the ground of coal rock in a goaf under a coal mine at intervals in sequence, and the roadway electrode station, the goaf electrode station and the main roadway reference electrode station are electrode stations with the same structure; every electrode station all includes detection wire, flexible graphite cloth, wire net, graphite mucilage base, ground connection metal electrode, and the layering sets up from top to bottom flexible graphite cloth, is located the interlaminar wire net that sets up of flexible graphite cloth, and the below of the flexible graphite cloth that is located wire net below sets up graphite mucilage base, and perpendicular through connection ground connection metal electrode on the four corners of flexible graphite cloth, wire net and the graphite mucilage base of layering setting detects the wire and connects on the assembly that comprises flexible graphite cloth, wire net, graphite mucilage base and ground connection metal electrode.
As a preferable scheme of the invention, the detection wire consists of mica paper wrapping nickel wires and high-temperature resistant insulating glass fibers, and the temperature resistance of the detection wire is 1000 ℃.
As another preferable scheme of the invention, the flexible graphite cloth is prepared from graphite, cotton yarn, glass fiber and carbonized fiber through a synthesis process, and the solid state resistivity of the flexible graphite cloth is 0.06 Ω & m.
As another preferable aspect of the present invention, the wire mesh is woven from nickel alloy wires, stainless steel wires and copper wires.
As another preferable scheme of the invention, the graphite cement base is prepared from superfine flake graphite powder, conductive clay, an organic solvent and a resin adhesive, and is in a semisolid state, and the tolerance temperature of the graphite cement base is 1000 ℃.
As another preferable aspect of the present invention, the grounding metal electrode is made of a nickel alloy or stainless steel material.
On the other hand, the invention provides a layout method of an electrode station network system for goaf fire source detection, which comprises the following steps:
(1) Before laying, firstly measuring the resistivity rho of coal and rock on the ground in the goaf, and calculating the theoretical grounding resistance R of a single electrode station g And thus the theoretical ground resistance R of the electrode station g Determining the size of the pre-arranged electrode station according to the standard;
(2) Respectively determining the arrangement space of the roadway electrode stations, the arrangement space of the goaf electrode stations and the arrangement space of the main roadway reference electrode stations;
(3) Then, selecting layout positions in the underground goaf of the coal mine, arranging roadway electrode stations and main roadway reference electrode stations at intervals below the ground of coal rocks close to one side of a coal pillar, and arranging goaf electrode stations at intervals below the ground of coal rocks in the middle positions of a front roadway and a secondary roadway;
(4) After the layout positions are selected, pit opening is carried out on the coal rock ground surface on which the electrode stations are arranged according to the size and the spacing determined in the step (1), and the coal rock surface in the pit is flattened, so that the pit bottom is ensured to be a fresh raw coal rock surface;
(5) Pouring and coating graphite cement in the pit to form a graphite cement base, wherein the thickness of the graphite cement base depends on the flatness of the coal rock surface in the pit, so that the upper surface of the static graphite cement base completely passes through the fresh raw coal rock surface at the bottom of the pit;
(6) Paving a layer of flexible graphite cloth above the graphite cement matrix in the pit, paving a wire mesh above the layer of flexible graphite cloth, and paving a layer of flexible graphite cloth above the wire mesh;
(7) The grounding metal electrode is nailed into the ground from four corner edge positions of the upper flexible graphite cloth through the wire mesh, the lower flexible graphite cloth and the graphite cement matrix; then connecting the detection lead on a combination body formed by flexible graphite cloth, a lead net, a graphite cement base and a grounding metal electrode and leading the combination body out of the pit on the coal rock ground;
(8) Thirdly, sequentially connecting the detection lead of each electrode station to a ground resistance test instrument, correspondingly testing the paving effect of each electrode station, ensuring that the actual testing parameter error of each electrode station is not more than 20% of the design error, and filling broken stone in a pit and tamping if the actual testing parameter error of each electrode station meets the requirement; if the requirements are not met, the flexible graphite cloth area and the number of the grounding metal electrodes are increased or the graphite mucilage is poured around the flexible graphite cloth until the requirements are met.
Further, the coal rock resistivity rho is measured by a rock resistivity measuring instrument, and the theoretical ground resistance R of a single electrode station g The calculation formula of (2) is as follows:
wherein R is 1 Is the grounding resistance (omega) of the flexible graphite cloth, R 2 R is the ground resistance (Ω) of the grounded metal electrode m The flexible graphite is grounded and the mutual grounding resistance (omega) between the grounded metal electrodes is arranged;
grounding resistance R of flexible graphite cloth 1 The calculation formula of (2) is as follows:
wherein ρ is the resistivity (Ω·m) of the coal rock, r is the equivalent area circle radius of the flexible graphite cloth, and h is the thickness from the flexible graphite cloth on the upper layer to the ground of the coal rock;
the grounding resistance R of the grounding metal electrode 2 The calculation formula of (2) is as follows:
wherein ρ is the resistivity of the coal rock (Ω·m), L R For the length (m) of each grounded metal electrode, b is the radius (m), n of the grounded metal electrode R The number of grounded metal electrodes arranged on the area S;
the flexible graphite cloth is grounded and the inter-grounding resistor R between the grounded metal electrodes m The calculation formula of (2) is as follows:
wherein->
Wherein: ρ is the resistivity of the coal rock (Ω·m), L R For the length (m), r of each grounded metal electrode 1 In order to reach the long half shaft of the equipotential surface of the end part of the grounding metal electrode, r is the equivalent area circle radius of the flexible graphite cloth.
Further, the arrangement distance between the roadway electrode stations, the arrangement distance between the goaf electrode stations and the arrangement distance between the main roadway reference electrode stations are set according to the spontaneous combustion fire level of the coal seam, the development condition of a crack structure and the distribution characteristics of mining space around a fire source detection working face.
Further, in the step (6), a graphite cement is poured between the two layers of flexible graphite cloth and the wire mesh between the two layers of flexible graphite cloth so as to discharge the interlayer pores.
Further, in the step (5), the upper surface of the graphite cement base is 1cm or more above the fresh raw coal rock surface of the pit bottom.
Further, in the step (7), the depth of the ground metal electrode to be driven into the ground is 0.2m.
Further, in the step (8), the thickness of the crushed stone filled in the pit is more than 0.3 m.
In still another aspect, the invention provides a testing method of an electrode station network system for goaf fire source detection, the ground resistance testing instrument is used for testing the laying effect of each electrode station, the ground resistance testing instrument is provided with a measuring dial, a generator rotating handle, a galvanometer, a multiplying power scale, a probe and three connecting ends, the three connecting ends are respectively an E end, a P end and a C end, and the P end and the C end are respectively connected with the probe;
two probes connected to the P end and the C end of a ground resistance testing instrument are respectively inserted into the ground along the radiation direction of a tested electrode station in the electrode station network system, the insertion depth is 0.4m, and the E end of the ground resistance testing instrument is connected with a detection lead of the tested electrode station; after the ground resistance test instrument is horizontally placed, checking whether a pointer of a galvanometer points to a central line; setting the multiplying power scale at the maximum multiplying power, slowly rotating the generator rotating handle, and simultaneously rotating the measuring dial to enable the pointer of the galvanometer to point to the central line; when the pointer of the galvanometer is close to balance, the rotating handle of the generator is accelerated to enable the rotating speed to be more than 120r/min, and meanwhile, the measuring dial is adjusted to enable the pointer of the galvanometer to point to the central line; if the reading of the measurement dial is too small, and the reading is not easy to read accurately, the magnification scale is too large; at this time, the multiplying power scale is set at a smaller multiplying power, the measuring dial is readjusted, the pointer of the galvanometer points to the central line, and accurate readings are read;
calculating a measurement result of the actual measured grounding resistance R of the electrode station, namely, the actual measured grounding resistance R=multiplying power scale reading x measuring scale reading; when the actual measured grounding resistance R and the theoretical grounding resistance R of the electrode station g If the error exceeds 100%, the tested electrode station is considered to be laid out as unsatisfactory, and must be handled or re-laid.
The beneficial effects of the invention are as follows:
the electrode station arranged by the invention has the effects of high temperature resistance, corrosion resistance, good stability and high detection precision, and is extremely suitable for detecting hidden fire sources in a coal mine goaf in an extreme environment in a coal mine.
Drawings
Fig. 1 is a schematic diagram of an embodiment of an electrode station network system according to the present invention.
Fig. 2 is a schematic structural view of the electrode station of the present invention.
FIG. 3 is a schematic diagram of a ground resistance tester according to the present invention.
The marks in the figure: 1 is a roadway electrode station; 2 is a goaf electrode station; 3 is a detection wire; 4 is a main lane reference electrode station; 5 is a grounded metal electrode; 6 is flexible graphite cloth; 7 is a graphite mucilage base; 8 is a wire mesh; 9 is a ground resistance test instrument; 10 is a measurement dial; 11 is a generator rotating handle; 12 is a galvanometer; 13 is the multiplying power scale; 14 is a probe.
Detailed Description
In order to make the technical problems, technical schemes and beneficial effects solved by the invention more clear, the invention is further described in detail below with reference to the accompanying drawings and the detailed description. It should be understood that the detailed description is presented by way of example only and is not intended to limit the invention.
Referring to fig. 1 and 2, the electrode station network system for goaf fire source detection provided by the embodiment of the invention comprises a roadway electrode station 1, a goaf electrode station 2 and a main roadway reference electrode station 4, wherein the roadway electrode station 1, the goaf electrode station 2 and the main roadway reference electrode station 4 are respectively arranged below the ground of coal rock in a goaf under a coal mine in sequence at intervals, and the roadway electrode station 1, the goaf electrode station 2 and the main roadway reference electrode station 4 are electrode stations with the same structure; every electrode station all includes detection wire 3, flexible graphite cloth 6, wire net 8, graphite cement base 7, ground metal electrode 5, the layering sets up from top to bottom of flexible graphite cloth 6, be located the interlaminar wire net 8 that sets up of flexible graphite cloth 6, the below of the flexible graphite cloth 6 that is located wire net 8 below sets up graphite cement base 7, perpendicular through connection ground metal electrode 5 on the four corners of flexible graphite cloth 6 that the layering set up, wire net 8 and graphite cement base 7, detection wire 3 is connected on the assembly that comprises flexible graphite cloth 6, wire net 8, graphite cement base 7 and ground metal electrode 5.
The detection lead 3 consists of mica paper wrapping nickel wires and high-temperature resistant insulating glass fibers, and the temperature resistance of the detection lead 3 is 1000 ℃.
The flexible graphite cloth 6 is made of graphite, cotton yarn, glass fiber and carbonized fiber through a synthetic process, and the solid state resistivity of the flexible graphite cloth 6 is 0.06 Ω·m.
The wire mesh 8 is woven by nickel alloy wires, stainless steel wires and copper wires.
The graphite cement base 7 is made of superfine flake graphite powder, conductive clay, an organic solvent and a resin adhesive, the graphite cement base 7 is in a semisolid state, and the tolerance temperature of the graphite cement base 7 is 1000 ℃.
The grounding metal electrode 5 is made of nickel alloy and stainless steel materials.
The electrode station composed of the detection lead 3, the flexible graphite cloth 6, the lead net 8, the graphite cement base 7 and the grounding metal electrode 5 is arranged to form an electrode station net system, so that the electrode station net system has the effects of high temperature resistance, corrosion resistance and long-term stability maintenance.
The electrode station network system layout method for goaf fire source detection provided by the embodiment of the invention comprises the following steps:
(1) Taking the detection precision and the optimal coupling grounding effect into consideration; before laying, firstly measuring the resistivity rho of coal and rock on the ground in a goaf, and calculating the theoretical grounding resistance R of a single electrode station g And thus the theoretical ground resistance R of the electrode station g The arrangement space of the roadway electrode stations 1, the arrangement space of the goaf electrode stations 3 and the arrangement space of the main roadway reference electrode stations 4 are respectively determined according to the determined size of the pre-arranged electrode stations;
(2) Then, selecting layout positions in the underground goaf of the coal mine, arranging roadway electrode stations 1 and main roadway reference electrode stations 4 at intervals below the ground of coal rocks close to one side of a coal pillar, and arranging goaf electrode stations 2 at intervals below the ground of coal rocks in the middle of a front roadway and a secondary roadway; the geological stress stabilization area far away from the structural and lithologic interfaces is selected as far as possible, the production operation of the underground coal mine is not influenced, and the underground coal mine is not easy to damage.
(3) After the layout positions are selected, pit opening is carried out on the coal rock ground surface on which the electrode stations are arranged according to the size and the spacing determined in the step (1), and the coal rock surface in the pit is flattened, so that the pit bottom is ensured to be a fresh raw coal rock surface;
(4) Pouring graphite cement in the pit to form a graphite cement base 7, wherein the thickness of the graphite cement base 7 depends on the flatness of the coal rock surface in the pit, and the upper surface of the static graphite cement base 7 is ensured to completely overflow the fresh raw coal rock surface at the bottom of the pit; specifically, the upper surface of the graphite cement base 7 is 1cm or more above the fresh raw coal rock face of the pit bottom.
(5) Paving a layer of flexible graphite cloth 6 above the graphite cement base 7 in the pit, paving a wire mesh 8 above the layer of flexible graphite cloth 6, and paving a layer of flexible graphite cloth 6 above the wire mesh 8; in order to ensure the contact coupling property of the conductive net 8 and the flexible graphite cloth 6 and simultaneously avoid the natural oxidation of the conductive net 8 due to long-term exposure, graphite mucilage is poured between the laid two layers of flexible graphite cloth 6 and the conductive net 8 between the two layers of flexible graphite cloth so as to discharge interlayer pores.
(6) The grounding metal electrode 5 is nailed into the ground from the four corner edge positions of the upper flexible graphite cloth 6 vertically through the wire mesh 8, the lower flexible graphite cloth 6 and the graphite cement base 7, and the depth of the grounding metal electrode 5 nailed into the ground is 0.2m; then the detection lead 3 is connected to the combination body formed by the flexible graphite cloth 6, the lead net 8, the graphite mucilage base 7 and the grounding metal electrode 5 and is led out of the pit on the coal rock ground;
(7) Thirdly, sequentially connecting the detection lead 3 of each electrode station to a ground resistance test instrument 9, correspondingly testing the paving effect of each electrode station, ensuring that the actual testing parameter error of each electrode station is not more than 20% of the design error, and if the actual testing parameter error of each electrode station meets the requirement, filling broken stone in a pit and tamping, wherein the thickness of the filled broken stone is more than 0.3 m; if the requirements are not met, the area of the flexible graphite cloth 6 and the number of the grounding metal electrodes 5 are increased or the graphite adhesive cement is poured around the flexible graphite cloth 6 until the requirements are met.
The resistivity rho of the coal rock is measured by a rock resistivity measuring instrument, and the theoretical grounding resistance R of a single electrode station g The calculation formula of (2) is as follows:
wherein R is 1 The ground resistance (omega) of the flexible graphite cloth 6, R 2 For the ground resistance (Ω) of the ground metal electrode 5, R m The flexible graphite cloth 6 is grounded and the grounding metal electrode 5 is grounded with each other with a resistance (omega);
grounding resistance R of flexible graphite cloth 6 1 The calculation formula of (2) is as follows:
wherein ρ is the resistivity (Ω·m) of the coal rock, r is the equivalent area circle radius of the flexible graphite cloth 6, and h is the thickness from the flexible graphite cloth 6 on the upper layer to the ground of the coal rock;
the grounding resistance R of the grounding metal electrode 2 The calculation formula of (2) is as follows:
wherein ρ is the resistivity of the coal rock (Ω·m), L R For the length (m) of each grounded metal electrode 5, b is the radius (m), n of the grounded metal electrode 5 R The number of grounded metal electrodes 5 arranged on the area S;
the flexible graphite cloth 6 is grounded and the grounding resistance R is mutually grounded between the grounded metal electrode 5 m The calculation formula of (2) is as follows:
wherein->
Wherein: ρ is the resistivity of the coal rock (Ω·m), L R For the length (m), r of each grounded metal electrode 5 1 In order to reach the long half shaft of the end equipotential surface of the grounding metal electrode 5, r is the equivalent area circle radius of the flexible graphite cloth 6.
According to the electrode station theory, the grounding resistance R g The calculation method of (1) can know that the electrode station theory grounding resistance R g In inverse proportion to the areas of the flexible graphite cloth 6 and the grounding metal electrode 5, the hardness of coal and rock in the underground environment is high, and the laying depth of the grounding metal electrode 5 is shallow, so that the area of the flexible graphite cloth 6 plays a decisive role in the grounding effect, and the larger the grounding area is, the lower the grounding resistance is.
Theoretical grounding resistance R of electrode station g The ratio of the resistivity rho of the coal rock to the resistivity rho of the coal rock is set as a, and when the electrode station is in theory, the grounding resistance R g When the ratio of the resistivity rho to the resistivity rho of the coal rock is smaller than 1/2, the ground area is too small, and the resistance reducing effect is poor; when electrode station theory grounding resistance R g When the ratio of the earth resistance to the resistivity rho of the coal rock is larger than 1/4, the reduction of the earth resistance is not obvious, and the utilization rate of the electrode material is greatly reduced. Therefore, the flexible graphite cloth 6 is designed to have an area of 1/4<a<1/2, comprehensively considering the relation between the laying cost of the electrode station and the resistance reducing effect.
The arrangement distance between the roadway electrode stations 1, the arrangement distance between the goaf electrode stations 2 and the arrangement distance between the main roadway reference electrode stations 4 are set according to the spontaneous combustion fire level of the coal seam, the development condition of a crack structure and the distribution characteristics of mining space around a fire source detection working face.
Specifically, the basic distance between the electrode stations is set according to the spontaneous combustion fire level of the coal seam: setting the basic distance between electrode stations to be not less than 20m; setting the basic distance between electrode stations to be not less than 30m; the spontaneous combustion and ignition grade of the coal bed is a grade easy to be spontaneous combustion, and the basic distance between the electrode stations is set to be not less than 40m.
Specifically, the basic spacing of the electrode stations is set according to the crack structure development condition: the crack structure development section is provided with the basic interval of the electrode station not lower than 10m; the crack structure is a relatively developed section, and the basic interval between electrode stations is set to be not less than 20m.
Specifically, the basic spacing of the electrode stations is set according to the mining space distribution characteristics around the detection working face: the goaf and the roadway stagger complex sections, and the basic spacing of the electrode stations is set to be not less than 10m; and (3) in the section with more complex goaf and roadway distribution, setting the basic spacing of the electrode stations to be not less than 20m.
Referring to fig. 3, in the method for testing an electrode station network system for goaf fire source detection provided by the embodiment of the invention, the ground resistance testing instrument 9 is used for testing the laying effect of each electrode station, the ground resistance testing instrument 9 is provided with a measuring dial 10, a generator rotating handle 11, a galvanometer 12, a multiplying power scale 13, a probe 14 and three connecting ends, wherein the three connecting ends are respectively an end E, an end P and an end C, and the probes 14 are respectively connected to the end P and the end C; two probes 14 connected to the P end and the C end of the grounding resistance testing instrument 9 are respectively inserted into the ground along the radiation direction of one electrode station to be tested in the electrode station network system, the insertion depth is 0.4m, and the E end of the grounding resistance testing instrument 9 is connected with the detection lead 3 of the electrode station to be tested; after the ground resistance test instrument 9 is placed horizontally, checking whether the pointer of the galvanometer 12 points to the center line; the multiplying factor scale 13 is set to the maximum multiplying factor, and the generator handle 11 is slowly rotated while rotatingA measurement scale 10 having a pointer of a galvo 12 pointing toward the center line; when the pointer of the galvanometer 12 is close to balance, the generator rotating handle 11 is accelerated to rotate at a speed of more than 120r/min, and the measuring dial 10 is adjusted to lead the pointer of the galvanometer 12 to point to the central line; if the reading of the measurement dial 10 is too small, and the reading is not easy to read accurately, the magnification scale 13 is indicated to be too large; at this time, the magnification scale 13 is set at a smaller multiple, the measurement scale 10 is readjusted so that the pointer of the galvanometer 12 points on the centerline and an accurate reading is read; calculating the measurement result of the actual measured grounding resistance R of the electrode station, namely, the actual measured grounding resistance R=13 readings of the multiplying factor scale and 10 readings of the measuring dial; when the actual measured grounding resistance R and the theoretical grounding resistance R of the electrode station g If the error exceeds 100%, the tested electrode station is considered to be laid out as unsatisfactory, and must be handled or re-laid.
In addition, in order to ensure the detection precision of the fire source in the goaf, all the actually measured electrode station grounding resistances R in the electrode station network system must be ensured c Meets the requirement of relative uniformity, namely the standard deviation sigma of the ground resistance of all electrode stations is not more than the average value of the measured ground resistance of all electrode stations
10 percent of the total weight of the electrode station network is taken as a judging standard for the qualification of the electrode station network combination; the calculation formula of the standard deviation sigma of the grounding resistance of all the electrode stations is as follows: />
Wherein n is the number of electrode stations in the electrode station network; r is R ci The measured grounding resistance of the ith electrode station;
the measured ground resistance average value of all electrode stations; sigma is the standard deviation of the ground resistance of all electrode stations.
It should be understood that the foregoing detailed description of the present invention is provided for illustration only and is not limited to the technical solutions described in the embodiments of the present invention, and those skilled in the art should understand that the present invention may be modified or substituted for the same technical effects; as long as the use requirement is met, the invention is within the protection scope of the invention.
Claims (10)
1. An electrode station network system for goaf fire source detection, which is characterized in that: the coal mine underground goaf electrode system comprises a roadway electrode station, a goaf electrode station and a main roadway reference electrode station, wherein the roadway electrode station, the goaf electrode station and the main roadway reference electrode station are respectively and sequentially arranged below the ground of coal rock in the underground goaf of a coal mine at intervals, and the roadway electrode station, the goaf electrode station and the main roadway reference electrode station are electrode stations with the same structure; every electrode station all includes detection wire, flexible graphite cloth, wire net, graphite mucilage base, ground connection metal electrode, and the layering sets up from top to bottom flexible graphite cloth, is located the interlaminar wire net that sets up of flexible graphite cloth, and the below of the flexible graphite cloth that is located wire net below sets up graphite mucilage base, and perpendicular through connection ground connection metal electrode on the four corners of flexible graphite cloth, wire net and the graphite mucilage base of layering setting detects the wire and connects on the assembly that comprises flexible graphite cloth, wire net, graphite mucilage base and ground connection metal electrode.
2. An electrode station network system for goaf fire source detection as claimed in claim 1, wherein: the detection wire consists of mica paper wrapping nickel wires and high-temperature resistant insulating glass fibers, and the temperature resistance of the detection wire is 1000 ℃.
3. An electrode station network system for goaf fire source detection as claimed in claim 1, wherein: the flexible graphite cloth is made of graphite, cotton yarn, glass fiber and carbonized fiber through a synthetic process, and the solid state resistivity of the flexible graphite cloth is 0.06 Ω & m.
4. An electrode station network system for goaf fire source detection as claimed in claim 1, wherein: the wire mesh is formed by weaving nickel alloy wires, stainless steel wires and copper wires.
5. An electrode station network system for goaf fire source detection as claimed in claim 1, wherein: the graphite cement base is made of superfine flake graphite powder, conductive clay, an organic solvent and a resin adhesive, and is in a semisolid state, and the tolerance temperature of the graphite cement base is 1000 ℃.
6. An electrode station network system for goaf fire source detection as claimed in claim 1, wherein: the grounding metal electrode is made of nickel alloy and stainless steel materials.
7. A layout method of an electrode station network system for goaf fire source detection is characterized by comprising the following steps: the method comprises the following steps:
(1) Before laying, firstly measuring the resistivity rho of coal and rock on the ground in the goaf, and calculating the theoretical grounding resistance R of a single electrode station g And thus the theoretical ground resistance R of the electrode station g Determining the size of the pre-arranged electrode station according to the standard;
(2) Respectively determining the arrangement space of the roadway electrode stations, the arrangement space of the goaf electrode stations and the arrangement space of the main roadway reference electrode stations;
(3) Then, selecting layout positions in the underground goaf of the coal mine, arranging roadway electrode stations and main roadway reference electrode stations at intervals below the ground of coal rocks close to one side of a coal pillar, and arranging goaf electrode stations at intervals below the ground of coal rocks in the middle positions of a front roadway and a secondary roadway;
(4) After the layout positions are selected, pit opening is carried out on the coal rock ground surface on which the electrode stations are arranged according to the size and the spacing determined in the step (1), and the coal rock surface in the pit is flattened, so that the pit bottom is ensured to be a fresh raw coal rock surface;
(5) Pouring and coating graphite cement in the pit to form a graphite cement base, wherein the thickness of the graphite cement base depends on the flatness of the coal rock surface in the pit, so that the upper surface of the static graphite cement base completely passes through the fresh raw coal rock surface at the bottom of the pit;
(6) Paving a layer of flexible graphite cloth above the graphite cement matrix in the pit, paving a wire mesh above the layer of flexible graphite cloth, and paving a layer of flexible graphite cloth above the wire mesh;
(7) The grounding metal electrode is nailed into the ground from four corner edge positions of the upper flexible graphite cloth through the wire mesh, the lower flexible graphite cloth and the graphite cement matrix; then connecting the detection lead on a combination body formed by flexible graphite cloth, a lead net, a graphite cement base and a grounding metal electrode and leading the combination body out of the pit on the coal rock ground;
(8) Thirdly, sequentially connecting the detection lead of each electrode station to a ground resistance test instrument, correspondingly testing the paving effect of each electrode station, ensuring that the actual testing parameter error of each electrode station is not more than 20% of the design error, and filling broken stone in a pit and tamping if the actual testing parameter error of each electrode station meets the requirement; if the requirements are not met, the flexible graphite cloth area and the number of the grounding metal electrodes are increased or the graphite mucilage is poured around the flexible graphite cloth until the requirements are met.
8. The method for arranging the electrode station network system for goaf fire source detection according to claim 7, wherein the method comprises the following steps: the resistivity rho of the coal rock is measured by a rock resistivity measuring instrument, and the theoretical grounding resistance R of a single electrode station g The calculation formula of (2) is as follows:
wherein R is 1 Is the grounding resistance (omega) of the flexible graphite cloth, R 2 R is the ground resistance (Ω) of the grounded metal electrode m The flexible graphite is grounded and the mutual grounding resistance (omega) between the grounded metal electrodes is arranged;
grounding resistance R of flexible graphite cloth 1 The calculation formula of (2) is as follows:
wherein ρ is the resistivity (Ω·m) of the coal rock, r is the equivalent area circle radius of the flexible graphite cloth, h is the upper flexible graphite cloth to the coal rockThe thickness of the stone floor;
the grounding resistance R of the grounding metal electrode 2 The calculation formula of (2) is as follows:
wherein ρ is the resistivity of the coal rock (Ω·m), L R For the length (m) of each grounded metal electrode, b is the radius (m), n of the grounded metal electrode R The number of grounded metal electrodes arranged on the area S;
the flexible graphite cloth is grounded and the inter-grounding resistor R between the grounded metal electrodes m The calculation formula of (2) is as follows:
wherein->
Wherein: ρ is the resistivity of the coal rock (Ω·m), L R For the length (m), r of each grounded metal electrode 1 In order to reach the long half shaft of the equipotential surface of the end part of the grounding metal electrode, r is the equivalent area circle radius of the flexible graphite cloth.
9. The method for arranging the electrode station network system for goaf fire source detection according to claim 7, wherein the method comprises the following steps: the arrangement distance between the roadway electrode stations, the arrangement distance between the goaf electrode stations and the arrangement distance between the main roadway reference electrode stations are set according to spontaneous combustion fire levels of coal beds, the development condition of crack structures and the distribution characteristics of mining space around a fire source detection working face.
10. A test method of an electrode station network system for goaf fire source detection is characterized by comprising the following steps: the method comprises the following steps:
the ground resistance testing instrument as claimed in claim 7 is used for testing the paving effect of each electrode station, wherein the ground resistance testing instrument is provided with a measuring dial, a generator rotating handle, a galvanometer, a multiplying power scale, a probe and three connecting ends, namely an E end, a P end and a C end, and the probes are respectively connected to the P end and the C end;
two probes connected to the P end and the C end of a ground resistance testing instrument are respectively inserted into the ground along the radiation direction of a tested electrode station in the electrode station network system, the insertion depth is 0.4m, and the E end of the ground resistance testing instrument is connected with a detection lead of the tested electrode station; after the ground resistance test instrument is horizontally placed, checking whether a pointer of a galvanometer points to a central line; setting the multiplying power scale at the maximum multiplying power, slowly rotating the generator rotating handle, and simultaneously rotating the measuring dial to enable the pointer of the galvanometer to point to the central line; when the pointer of the galvanometer is close to balance, the rotating handle of the generator is accelerated to enable the rotating speed to be more than 120r/min, and meanwhile, the measuring dial is adjusted to enable the pointer of the galvanometer to point to the central line; if the reading of the measurement dial is too small, and the reading is not easy to read accurately, the magnification scale is too large; at this time, the multiplying power scale is set at a smaller multiplying power, the measuring dial is readjusted, the pointer of the galvanometer points to the central line, and accurate readings are read;
calculating a measurement result of the actual measured grounding resistance R of the electrode station, namely, the actual measured grounding resistance R=multiplying power scale reading x measuring scale reading; when the actual measured grounding resistance R and the theoretical grounding resistance R of the electrode station g If the error exceeds 100%, the tested electrode station is considered to be laid out as unsatisfactory, and must be handled or re-laid.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310049327.7A CN116224443A (en) | 2023-02-01 | 2023-02-01 | Electrode station network system for goaf fire source detection, layout method and test method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310049327.7A CN116224443A (en) | 2023-02-01 | 2023-02-01 | Electrode station network system for goaf fire source detection, layout method and test method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116224443A true CN116224443A (en) | 2023-06-06 |
Family
ID=86577972
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310049327.7A Pending CN116224443A (en) | 2023-02-01 | 2023-02-01 | Electrode station network system for goaf fire source detection, layout method and test method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116224443A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117348090A (en) * | 2023-10-13 | 2024-01-05 | 山东科技大学 | Coal spontaneous combustion underground detection system and method based on natural potential method |
-
2023
- 2023-02-01 CN CN202310049327.7A patent/CN116224443A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117348090A (en) * | 2023-10-13 | 2024-01-05 | 山东科技大学 | Coal spontaneous combustion underground detection system and method based on natural potential method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Gudmundsson | Geometry, formation and development of tectonic fractures on the Reykjanes Peninsula, southwest Iceland | |
| CN108802828B (en) | Drilling grouting curtain quality detection method | |
| CN116224443A (en) | Electrode station network system for goaf fire source detection, layout method and test method thereof | |
| CN109461359A (en) | A kind of aqueous geological structure forward probe method in tunnel | |
| CN110501387B (en) | Resistivity logging physical simulation method for sediments containing natural gas hydrates | |
| CN202256504U (en) | Soil resistivity test probe in well | |
| CN102444111B (en) | Underground cave radiography detecting method | |
| Young et al. | Archaeological applications of resistivity and magnetic methods at Fort Wilkins State Park, Michigan | |
| CN207714393U (en) | A kind of vertical plastic spreading seepage proof curtain leak detection apparatus | |
| CN116540309A (en) | Method for detecting ground pre-grouting effect of vertical shaft through cross-hole resistivity CT | |
| Nunn et al. | In situ seismic and electrical measurements of fracture anisotropy in the Lincolnshire Chalk | |
| CN112925028B (en) | Detection method of bedrock fracture dominant channel based on high-density electrical method | |
| Hu et al. | Manual wiring measurement of DC deep well grounding resistance | |
| Paria et al. | Geophysical-geotechnical investigation of an old tailings dam from a mine in the peruvian highland | |
| CN102147483B (en) | Groundwater-recharge bipolar double-meter electric well logging method | |
| CN214252606U (en) | Separated tunnel multi-polar-distance array observation device | |
| Boys | Resistivity testing for earthing safety | |
| West et al. | Precise measurement of deep electrical anomalies | |
| Buhle et al. | Electrical earth resistivity surveying in Illinois | |
| Koehn et al. | Enhanced analysis of landslide failure mechanisms in the Ozark Plateau Region with electrical resistivity tomography | |
| Zhaoguang et al. | Application of geological drilling combined with high-density resistance in island structure permafrost survey | |
| Barriga Paria et al. | Geological-Geotechnical Investigation of an Old Tailings Dam from a Mine in the Peruvian Highlands | |
| CN110865242B (en) | System and method for monitoring fracture electric field intensity | |
| Ahlbom et al. | Final disposal of spent nuclear fuel-geological, hydrogeological and geophysical methods for site characterization | |
| CN114660371A (en) | Shallow electrode construction method for long-term observation of fracture electric field |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |